1. Field of the Invention
The present invention relates in general to a process and catalyst for ring opening of cyclic compounds. More particularly, the invention concerns metal-supported oxide-based catalysts and a process for ring opening of cyclic compounds including derivatives of cyclopentane, cyclohexane, decaline, indane (indene), benzene, and naphthalene being present in diesel fuel in presence of hydrogen to linear or branched paraffinic molecules.
2. Description of the Related Art
One of the approaches to the improvement of the certain number of diesel fuel is to increase the content of paraffinic compounds with linear chains in the diesel fuel. The content of non-cyclic paraffins in the hydrocarbon mixture can be increased by carrying out ring opening of cycloparaffins formed upon hydrogenation of aromatic compounds present in the fuel.
Commercially available catalytic systems based on 1% Pt/H-Beta zeolite are disclosed in U.S. Pat. No. 5,382,730. The described catalysts exhibit rather high activity in ring opening of C.sub.6 cyclic compounds and are used in combination with isomerization catalysts to improve quality of a C.sub.5 -C.sub.6 downstream feed. In this case, however, a 1:3 mixture of normal and isoparaffins was formed at conversion rates of .about.80% at 230-270.degree. C. under high-pressure conditions. Another catalyst is proposed in U.S. Pat. No. 5,382,731 for ring opening of C.sub.6 cyclic compounds comprising a 1% Pt/WO.sub.3 /ZrO.sub.2 system. The performance of this catalyst is similar to that of Pt/H-Beta zeolite, at slightly different reaction conditions.
Only a very limited number of prior art publications is available, which are related to decalin conversion on zeolite and oxide catalysts. In most of these publications decalin cracking is studied, which leads to more than 100 products in the C1-C10 range. Decalin conversion has also been studied from the viewpoint of its cis-trans isomerization. There is no available reported data on decalin conversion on oxide catalysts.